Algodoo

added weight to pistons, connecting rods, cylinder walls, and flywheel
added stabilization hinges.
added springs and throttle as requested

You can change the throttle values to whatever you want on the laser colliders by selecting one and going the script menu.

for example, by changing sim.my.throttle = 10000 to whatever number you want

Hope this works for you

EDIT: made more powerful, replaced connecting rods with springs, tightened tolerances